<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.bootcss.com/vue/2.6.11/vue.min.js"></script>
    <style>
        .aa {
            border: #000000 solid 1px;
        }
        .bb {
            background-color: aquamarine;
        }
        .cc {
            font-size: 30px;
        }
    </style>
</head>
<body>
    <div id="app">

        <div v-bind:class="['aa','bb','cc']">
            Vue
        </div>

        <div v-bind:class="[p, p2, p3]">
            Vue2
        </div>

        <div v-bind:class="[ {'aa':flag},{'bb':flag2},{'cc':flag3}  ]">
            Vue3
        </div>

        <div v-bind:class="[ flag4 ? 'aa' : 'bb' ]">
            Vue4
        </div>

    </div>    
    <script>
        var app = new Vue({
            el: "#app",
            data: {
                p: "aa",
                p2: "bb",
                p3: "cc",
                flag: true,
                flag2: true,
                flag3: true,
                flag4: true
            }
        }); 
    </script>
</body>
</html>